Powertrain, generic · Auxiliary emission controls

P045D EGR B Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. EGR B is a second EGR valve next to valve A – on diesels with two EGR circuits the low-pressure valve, which takes exhaust after the particulate filter and feeds it in before the turbo compressor. GM's diesels of 2016–18 and FCA's 2.2-litre diesel in the Jeep Wrangler use it. P045D means the drive circuit of valve B is shorted to the supply, or the actuator draws overcurrent with the driver on (comparable to P0490 for valve A). The driver is switched off and EGR B stays inactive. GM lists this code among those that switch off the low-pressure EGR position control, but publishes no thresholds for it; the description follows the comparable valve A checks and CARB, which requires output circuits to be monitored.

Likely causes

Control wire shorted to a supply wire
Actuator motor shorted internally (overcurrent)
Moisture or corrosion in the connector
Engine module

Symptoms

  • Check engine light on
  • Low-pressure EGR switched off, possibly higher NOx
  • Usually no change in driving

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–700
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

egr valve blow pressure egr valveegr wiringengine control module

Related codes

P045CP045AP0490P044D

References: gsi.ext.gm.com, law.cornell.edu, patents.google.com.